Michael O'Sullivan is being treated for his injuries in the intensive care unit of Cork University Hospital.
The 25-year-old jump jockey was injured in a fall at Thurles on Thursday. Racing was delayed and ultmately abandoned as O'Sullivan received medical treatment and an air ambulance was called to the scene.
On Friday morning Dr Jennifer Pugh of the Irish Horseracing Regulatory Board said: "Michael is in the intensive care unit at Cork University Hospital, being treated for his injuries sustained at Thurles and is receiving the best medical care.
"Michael's family wish to express their gratitude for all the well wishes."
Famous racing family
O'Sullivan comes from a renowned Co Cork racing family.
His father William and uncle Eugene combined to win the Foxhunter Chase at Cheltenham in 1991 with Lovely Citizen. His cousin Maxine won the same race in 2020 on It Came To Pass, also trained by Eugene.
As a schoolboy, Michael O'Sullivan made an immediate impact as a point-to-point rider. He also rode a winner on the track in 2018. In 2019 he was champion under-21 rider in point-to-points with 16 winners.
He continued his studies at UCD and was conferred with a degree in Agricultural Science. He rode out for Gordon Elliott during that time and, by chance, struck up an association with owner-trained Barry Connell following a Punchestown bumper winner in May 2022 aboard Marine Nationale.
Famously, O'Sullivan kept the ride on that future star and had turned professional by the time he rode Marine Nationale to win the Grade 1 Royal Bond Novice Hurdle at Fairyhouse in December 2022.
The pair went on to even greater glory in the 2023 Supreme Novices' Hurdle at Cheltenham. On that same day O'Sullivan also rode Jazzy Matty to win the Fred Winter Juvenile Handicap Hurdle for Gordon Elliott.
The talented rider also won a Grade 1 novice hurdle at Leopardstown that season aboard the Connell-trained Good Land.
Last November Connell and O'Sullivan went their separate ways, allowing O'Sullivan the freedom to ride in France and Britain, as well as in Ireland. He has ridden 14 winners in Ireland this season, two in Britain and one in France.